Flexible transmission



Feb. 24, 1942. E, Q HORTON 2,274,295

FLEXIBLE TRANSMI SS ION Filed Aug. 3, 1959 .i l TQM u INVENTOR 750g/Y2 C//o/o/z ATTORNEYS Patented Feb. 24, 1942 FLEXIBLE TRANSMISSION Erwin C. Horton, Hamburg, N. Y., assiznor to Trico I roducts Corporation, Buffalo, N. Y.

Application August 3, 1939, Serial No. 288,196

(Cl. 'M -222)l 6 Claims.

This invention relates to a windshield cleaner and more particularly to the chain gear drive therefor.

The modern motor vehicle has its windshield -wiper operable through a exible transmission which facilitates the installation of th'e cleaner on a motor vehicle and which embodies a unit having a wiper shaft and a driving shaft therefor and connected thereto by chain sections engaging projections on the shafts. If the chains become dislodged or engaged with the wrong projection the wiper will likewise become displaced. Further, the shaft cannot with safety be oscillated in excess of 180 without upsetting the intended operation. f

It is an object of the present invention to prolvide a practical construction of chain gear in Fig. 3 is a detailed enlargement of the chain gear more clearly depicting the present invention, and

Fig. 4 is an enlarged detailed View more clearly showing the manner of engaging and disengaging the chain.

Referring more particularly to the drawing, the numeral I designates the cowl portion of the motor vehicle extending forwardlyfrom the base of the windshield 2. Disposed within an opening in the cowl is a housing 3 serving as a support for the wiper shaft 4, as well as an enclosure for the chain gear. Fixed on the wiper shaft 4 is the wiper` carrying arm 5, to the free upper end of which is connected the wiper, not shown.

The chain gear comprises a pair of wheels or mutilated sprockets 6 and 1, the wheel 6 being fixed to the wiper shaft 4, while the wheel 1 is fixed to a driving shaft 8, suitably journaled on a bracket po'rt-ion of the housing 3 beneath the cowl I for deriving its power from a suitable source to which it is connected by a link 9. The shaft 8 is shown as being angularly displaced with respect to the shaft 4 of which the chain transmission readily admits to facilitate the installation on angular windshields. The wheel 1 is depicted as having a radial arm l0' to which the link 9 is pivotally connected, as at II, so that when the link is reciprocated the wheel 1 will be oscillated about its axis. The two wlfeels are operatively connected by a chain'lZ so that when the lower wheel 1 is oscillated a similar movement will be transmitted to the wiper operating shaft 4.

The upper wheel 6 has one or more teeth I3, each being peculiarly shaped by broadening out with a flare from its base so that both the front and back edges of the tooth lie substantially radial. The circumferential length of the crest or top or each tooth, while beingA less th'an the longitudinal dimension of the opening in the engaged link ofthe chain, or the distance between adjacent cross bars I4 of the chain, is greater than its basal dimension. The tooth is, however, dimensioned so'as to have a greater distance between its trailing base edge and its advancing outer 'edge than the distance between adjoining cross bars of the chain. Consequently, with the rear cross bar of a link hugging the wheel at the base of the tooth it will be impossible for the link to swing its front cross bar over such leading outer edge and clear of the tooth. Therefore, the chain will follow under the wheel substantially as depicted in Fig. 3.

The action of the ch'ain being such that the front cross bar of the engaged link tends to swing outwardly about the pivotal axis of the next succeeding cross bar but is prevented because this radius is less than the extreme dimension of the tooth from its base, the link will be prevented from detaching itself from the tooth while under the pulling stress from the lower wheel 1. Wh'ere two teeth are provided on the sprocket 6, the opposing radial sides of the teeth, defining the slot I5, may be constructed parallel to each other as well as to the radius passing therebetween, The remote edges of the two teeth preferablytare radial, terminating outwardly in arcs I1 over which the adjacent cross bar may pass when the intermediate or trailing cross bar has first been manually lifted outwardly away from the wheel.

Consequently, the link will be prevented from accidental disengagement, but nevertheless permit authorized disengagement by bodily movement of the link radially of the tooth for a distance prior to swinging the forward bar over the corner I1. As shown in Fig. 3, the right hand night of the chain is pulling downwardly on the wh'eel B so that the front cross bar of the first engaged link is held in engagement with the /front edge o1' the tooth, while the adjacent cross bar within the slot I5 is confined toward the base of the tooth by the trailing portion of the chain which hugs close to t'he wheel as it takes over the upper arc thereof. When the wheel is oscillated in the Qppositedirection a similar action will take place regarding the other tooth which then will be the advancing one in that particular instance.

The opposite or lower ends ofY the chain are engaged with teeth I6, similarly shaped as teeth I3, on opposite sides of the radial arm I0 whereby the chain will be held from becoming disengaged when the slack ight is elevated above the horizontal.

It is, therefore, obvious that the chain may readily be engaged with and disengaged from the teeth when desired for purposes oi replacement or repair, but during operation Vthe chain is securely interlocked against accidental disengagement. The aring shape of the tooth gives a diagonal dimension greater than the link opening to thereby insure this.

The foregoing disclosure is illustrative of the inventive concept herein disclosed, which latter may be incorporated in other physical embodiments without departing from the scope or spirit of the invention claimed.

What is claimed is:

1. A flexible transmission of the character described, comprising a chain gear in which a wheel has a tooth engaged by a chain link and flaring from the base in the plane of rotation with a point on the leading edge at a substantial distance from its base being spaced from the base of the trailing edge of the tooth a distance greater than the length of the link opening, whereby on pivotal movement of the front end of the link away from the sprocket hub and about the back end as a point of fulcrum said front end will be obstructed by the tooth from passing freely thereover.n

2. A chain gear of the character described having a wheel with a chain anchoring tooth the crest portion of which is enlarged circumferentially, and a link having front and rear cross portions defining a tooth receiving opening and engageable with Ythe front and back edges of the tooth upon the outward swinging of the front cross portion, the longitudinal dimension of the link opening being greater than the circumferential dimension of the enlarged crest portion to permit manual placement of the link thereover, such dimension of the link opening being shorter than the distance between the leading corner of the crest portion and the basal point of engagement of the rear cross portion with the back face of the tooth.

3. A chain gear having a Wheel with a chain anchoring tooth flaring outwardly in a radial direction, and a chain link with a tooth receiving opening, the outer circumferential dimension of the tooth being substantially equal to the length of the link opening to permit reception of the tooth by theY opening when the link is moved bodily over the tooth, and a point on the leading edge at a substantial distance from its base being spaced from the base of the trailing edge a distance greater than the length of the link opening whereby to prevent disengagement of the link from the tooth during pivotal movement of the link about an axis at the base of the trailing edge.

4. A chain\ gear having a wheel with a chain anchoring tooth flaring outwardly in a radial direction, and a chain link with a tooth receiving opening, the outer circumferential dimension of the tooth being substantially equal to the length of the link opening to permit reception of the tooth by the opening when the link is moved bodily over the tooth, and a point on the leading edge at a substantial distance from its base being spaced from the base at the trailing'edge a distance greater than the length of the link opening to prevent one end of the link being lifted from 01T the tooth by pivotal movement about an axis adjacent the base of the trailing edge of the tooth, the transverse outer corner of the tooth at the leading edge being rounded.

l5. A chain engaging tooth of outwardly aring design to provide a greater circumferential dimension adjacent the top of the tooth than at the base thereof, a diagonal dimension of the tooth being greater than its circumferential dimension, and a chain link having a tooth receiving opening with a longitudinal dimension greater than the circumferential dimension and less than the diagonal dimension.

6. A exible transmission comprising a chain gear in which a wheel is provided with a link anchoring tooth, and a chain link engaging the tooth, the tooth having a maximum circumferential dimension less than the spacing between the forward and rearward cross portions of the link and a diagonal dimension between a point on the leading edge of the tooth at a substantial distance from its base and the base of the trailing edge of the tooth being greater than such spacing between the link cross portions whereby to prevent disengagement of the link froml the tooth during pivotal movement of the link about an axis at the base of the trailing edge.

ERWIN C. HORT'ON. 

